Police were called to a disturbance involving a number of people in Maidstone High Street at 3am on Sunday.
A 21-year-old man was found with stab injuries and pronounced dead at the scene.
Four men were injured and taken to hospital.
A 23-year-old man, two 21-year-old men and a 19-year-old man were arrested and remain in custody.
The street remained closed on Sunday morning while officers investigated the incident.
Anyone with information is asked to call Kent Police on 01622 604100, quoting 25-0224.